You can find 20-seven member states who may have conferred powers upon the EU institutions (other countries are tied on the EU in other ways). In exchange for conferring competences, EU states are assigned votes from the Council, seats in Parliament as well as a European Commissioner between other matters. https://european-news53208.blogzet.com/icc-seeking-arrest-warrants-for-hamas-leaders-and-israel-s-netanyahu-41957297